Methods of separating sugar juice, pith, and fiber from stalks



Aug. 25, 1953 METHODS OF SEPARATING SUGAR JUICE, PITH, AND FIBER FRO P. M. HORTON ETAL Filed Oct. 18, 1949 M sTAL-Ks ATTORNEYS Patented Aug. 25, 1953 METHODS OF SEPARATIN G SUGAR J UIOE,

PITH, AND FIBER FROM STALKS Paul M. Horton and Arthur G. Keller, Baton 8 Claims.

This invention relates to the treatment of sugar cane or other pith, fiber and sugar containing stalks such as sorgo, corn or maize, and the main object of the invention is to recover economically and substantially completely the sugar containing juices.

A further object is to recover all of the pith and all of the fibrous material, and in such form that they constitute valuable by-products.

The fiber is suitable for conversion into pulp by conventional paper making processes, while the pith can be employed as an absorbent in the manufacture of explosives, of animal feeds, and as animal litter or agricultural mulch.

Although various different types of sugar bearing stalks may be employed, bodiment hereinafter described is particularly adapted for the treatment of sugar cane. Our process, while ordinarily intended for use after the last mill in used on cane which has been shredded by passage through a conventional swing hammer mill. In other Words, our process, used after a swing hammer mill or shredder, can replace completely the conventional rolling mills used in cane sugar manufacture.

As a further feature, the juice extracted from the cane is filtered through a bed of the pith to remove suspended matter from the fiber, and preferably such bed is residual juice may be washed from the pith bed and the wash water returned to the system.

The present invention does not involve any improvements in any specific unit employed in the system, with the exception Therefore, in the accompanying drawings the different units are shown diagrammatically, and it will be understood that in commercial practice each of the units may be any one of various different types suitable for the purpose.

In the accompanying drawing one form of apparatus which may be used is diagrammatically illustrated.

In the apparatus as illustrated, the sugar cane is fed by a conveyor I I to knives l2 which cut the stalks into short sections. These are delivered to a hammer mill or shredder l3 which breaks up the sections of stalks and forms a mat which is delivered to a mill of any suitable type, and preferably that in which the material passes over a plurality of pairs of rollers and is pressed against each pair by a superposed roller so as to further crush the cane and squeeze out a major portion of the juice. A single mill may be employed, but it is preferable to employ a existing milling plants, can be a moving one, so that r:

of the juice filter. 53

State Univer and Mechanical College,

Application October 18, 1949, Serial No.

assignors to Board of Supervisors of sity and Agricultural Baton Rouge, La.

As diagrammatically ilfour sections or sets of I40, and the juice exdelivered to the second stantially free of the other.

The pith, suspended in water, is discharged from the mills I 6 through pipes I1, and the fibers are discharged through a chute or pipe H3. The mills It, as shown, are arranged in parallel, but they may be arranged in series, with the second taking the fiber and water from the first, but each separately discharging the pith. The beating and breaking up of the bagasse in the mills I6 is in the presence of water which may be delivered into the upper portion of through a pipe [9 WhlCh has separate branches, one leading to each mill Hi. There are illustrated two branches lQa and I919 for each mill, one discharging onto the fiber entering the mill and the other discharging into the material within the mill. The water delivered through the pipe i9 is taken from the system at a later point in the processing, as hereinafter described, and contains some sugar juice, from which pith and fibers substantially free of sugar have been removed.

The water discharged through the pipes l1, and which contains the major portion of the pith, has the pith separated therefrom by any suitable means. As shown, there is provided an inclined screen 20 onto which the pith and water are delivered, and by means of which they are 22. The pith separated at the screen is delivered through a pipe 23 and, as hereinafter explained, later used for filtering the juice delivered from the mill [4.

The water carrying the fiber separated in the mills l6, and substantially free of pith, is delivered by the pipes Hi to a tank 24, where the fiber settles to the bottom. The supernatant liquid which contains some sugar and fine floating material, is drawn off from the upper part of the tank through the pipe 25, and is returned to the mills l6 for wetting the bagasse which is being separated into pith and fiber.

In the form illustrated there are employed two of the mills l6 arranged in parallel. It will of course be obvious that these two may be arranged in series if desired, or that one might serve the purpose of the two.

Preferably an additional pith and fiber separating mill I611. is employed, which is arranged in series with the mills IBV To this 111111 16a there is delivered through the pipe 2B fiber which is drawn off from the tank 24, and which may still contain some pith and sugar juice.

The pith and sugar containing juice are delivered from this mill lfia through a pipe 21 to a screen 200., and the water containing. some residualsugar juice is returned to the mills 16 through the pipe l9, hereinbefore referred to, and

- used to wet the material being processed in the mills iii. The pith separated by the screen 2M is delivered through a pipe 29 which joins the pipe 23 carrying pith from the screen 20, and is used for'filtering as hereinafter described. The fiber from the mill liia is delivered to a tank 24a in which the fiber settles to the bottom, and the supernatant water is delivered through a pipe fill to wet the material being treated in the mill Via. The water containing somev juice and the settled fibers is withdrawn from the tank 2. h u a pipe 26a and delivered to a screen 2% which removes the fibers. The fibers may be further washed, if desired, by Water deliv red the screen by pipe and delivered through a pipe 3| for drying, storage, or other purpose. The washwater passing through the screen 201: is delivered through a pipe 32, and a portion of this may be delivered through pipe 33 where it, to-

gether with the water delivered through the pipe 30, is used to wet the material in the mill 16a.

The pith separated by the screens 20 and 20a and delivered through the pipes 23 and 29 are united, and all of this pith is delivered through the pipe 34 for the filtration of the juice, as hereinafter described.

All of the fiber separated in the mills l6 and settled in the tank 24, is delivered to the mill Hill. and all of the fiber separated in the mill Mia and settled in the tank 24a are separated from the liquid by the screen 20?), and delivered through the pipe 3| for storage.

The sugar juice separated from the pith in mill Isa goes back to mills 16; the sugar juice separated from the pith discharged from mills It goes through pipe 2! back to mill Mb; the sugar juice separated from fiber in tank 24 goes to mill lea, and a part of the sugar juice separated from fiber in tank 240. goes through pipe 33 to mill lBa. The pith, after being separated by the screens 2!! and 20a, is used to filter further solids from the juice. Residual sugar isv then washed from the filter bed by the, liquid which has passed through screen 2%, and the wash water is returned to the system.

As previously noted, the pith may be and pref erably is employed to form a filter bed for the sugar juice. The bed is preferably a progressively advancing one, to one end of which the pith is continuously delivered, and from the other end of which pith with impurities is continuously withdrawn. The pith, after serving as a filter, is washed, and the sugar returned to the system. For this purpose there is employed a closed loop conveyor for the filtering material, and which in structural design may embody certain parts similar to those shown in the Sinden Patents 2,155,874 and 2,465,287.

As diagrammatically illustrated there is provided an annular chamber 40 within which there is mounted an endless conveyor 4| which may be slowly driven in any suitable manner, and from any suitable source of power. Two portions 42 and 43 of the lower wall of the chamber are porous, and one of these forms the top wall of a collecting chamber 44 and the other forms the top wall of a collecting chamber 45. The pith collected on the screens 23 and 20a and delivered through the pipes 23 and 29, is conveyed through the pipe 34 to the chamber 40 adjacent to one end. The juice from mill [4 is delivered through pipe 22 to the chamber 45 adjacent to the rear end of the chamber 45, and in flowing through the pith being advanced by the conveyor. 4 is fil e ed. co lected in the chamber 45. and discharged from the system through the pipe 46. v

A portion of the wash water which has passed through the screen 2%, and delivered by the pipe 32, is conveyed by a pipe 4! to a point above the rear end of the chamber 44. It there flows through the filter bed to wash residual sugar juice from the bed, and collects in the chamber 34 from which it is returned to the system through pipe 48. The pith which is delivered to the conveyor through the pipe 34 is continuously advanced by the conveyor 4|. The residual sugar juice having been washed therefrom, the pith now drops into a pocket 49 on the lower side of an upper run of the conveyor and is discharged from the system through a pipe 50.

Thus, from the cane or other sugar bearing material delivered to the system by the conveyor H, there are produced three products. All of the sugar juice, substantially free of pith or fiber, is discharged from the system through the pipe 46; all oi the fiber washed free of pith is discharged through pipe 3|; and all of the pith which has been separated from the fiber and used as a filter bed is discharged from the system through the pipe 563. It will therefore be seen that'by our improved process the three main ingredients of claim as new anddesire to secure by Letters I Patent is:

1. The method of purifying sugar containing juice obtained from crushed stalks containing sugar, pith and fiber, said method including separating the juice from the crushed stalks, breaking up the crushed stalks, separating the pith from the fibers, in the presence of water, filtering" the juice through the pith, washing sugar juice from the pith, and returning the wash water to the stalks being broken up. V

2. The method of recovering valuable products from stalks having sugar containing juice, which removing sugar containing water from the pith and returning it to the stalks being crushed, removing sugar containing water from the fiber and returning it to the stalks being broken up.

3. The method of recovering valuable products the sugar juice through said bed.

4. The method of separating and recovering the pith and fibers of stalkshaving sugar conthe fibers, and returning said water to the pith stalks being broken up, delivering the pith to and forming therefrom a contlnuously advancing 6. The method of separating and recovering the sugar, juice, pith and fibers of sugar containing stalks, which includes continuously advancing being broken up.

7. The method of separating and recovering pith, fibers and sugar containing juices from the fibers, removing the fibers from the water containing sugar and pith, separating the pith from the water and returning the water and contained juice to the stalks being broken up, form- PAUL M. HORTON. ARTHUR G. KELLER.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Bringier July 29, 1873 Steffen May 21, 1901 Williams Dec. 24, 1901 Cromwell Aug. 7, 1906 McMullen Oct. 8, 1912 McMullen Oct. 8, 1912 Lindenberg Feb. 22, 1921 Campbell May 5, 1931 Number 

1. THE METHOD OF PURIFYING SUGAR CONTAINING JUICE OBTAINED FROM CRUSHED STALKS CONTAINING SUGAR, PITH AND FIBER, SAID METHOD INCLUDING SEPARATING THE JUICE FROM THE CRUSHED STALKS, BREAKING UP THE CRUSHED STALKS, SEPARATING THE PITH FROM THE FIBERS IN THE PRESENCE OF WATER, FILTERING THE JUICE THROUGH THE PITH, WASHING SUGAR JUICE FROM THE PITH, AND RETURNING THE WASH WATER TO THE STALKS BEING BROKEN UP. 